1 files changed, 93 insertions, 0 deletions
diff --git a/Homework/cs5260/consumer/dao/S3WidgetDao.ts b/Homework/cs5260/consumer/dao/S3WidgetDao.ts
new file mode 100644
index 0000000..d5aee72
--- /dev/null
+++ b/Homework/cs5260/consumer/dao/S3WidgetDao.ts
@@ -0,0 +1,93 @@
+import { WidgetT, Widget } from "@/shared/schema";
+import { WidgetDAO } from ".";
+import {
+  DeleteObjectCommand,
+  GetObjectCommand,
+  NoSuchKey,
+  PutObjectCommand,
+  S3Client,
+} from "@aws-sdk/client-s3";
+import { S3WidgetKeyGenerator } from "./keys";
+import { TracingLogger } from "@/consumer/log";
+
+export class S3WidgetDAO implements WidgetDAO {
+  private bucket: string;
+  private s3Client: S3Client;
+  private widgetKeyGenerator: S3WidgetKeyGenerator;
+  private logger: TracingLogger;
+
+  constructor(
+    bucket: string,
+    s3Client: S3Client,
+    widgetKeyGenerator: S3WidgetKeyGenerator,
+    logger: TracingLogger
+  ) {
+    this.bucket = bucket;
+    this.s3Client = s3Client;
+    this.widgetKeyGenerator = widgetKeyGenerator;
+    this.logger = logger;
+  }
+
+  public async retrieve(widget: WidgetT) {
+    const key = this.widgetKeyGenerator.fromWidget(widget);
+
+    this.logger.info(
+      `getting Widget=(${widget.id}) in Bucket=(${this.bucket})`
+    );
+
+    const retrievalRequest = new GetObjectCommand({
+      Bucket: this.bucket,
+      Key: key,
+    });
+
+    try {
+      const objectResp = await this.s3Client.send(retrievalRequest);
+      const textRepr = await objectResp.Body?.transformToString();
+
+      if (textRepr) {
+        this.logger.info(`retrieved WidgetObject=(${widget.id}) from S3`);
+        return Widget.parse(JSON.parse(textRepr));
+      }
+    } catch (e: unknown) {
+      if (e instanceof NoSuchKey) {
+        return;
+      }
+      throw e;
+    }
+  }
+
+  public async save(widget: WidgetT) {
+    const key = this.widgetKeyGenerator.fromWidget(widget);
+
+    this.logger.info(`saving Widget=(${widget.id}) in Bucket=(${this.bucket})`);
+
+    const putReq = new PutObjectCommand({
+      Bucket: this.bucket,
+      Key: key,
+      Body: JSON.stringify(widget, null, 2),
+    });
+
+    await this.s3Client.send(putReq);
+
+    this.logger.info(`successfully saved Widget=(${widget.id}) in S3`);
+    return widget;
+  }
+
+  public async delete(widget: WidgetT) {
+    const key = this.widgetKeyGenerator.fromWidget(widget);
+
+    this.logger.info(
+      `deleting Widget=(${widget.id}) in Bucket=(${this.bucket})`
+    );
+
+    const deleteReq = new DeleteObjectCommand({
+      Key: key,
+      Bucket: this.bucket,
+    });
+
+    await this.s3Client.send(deleteReq);
+
+    this.logger.info(`successfully deleted Widget=(${widget.id}) in S3`);
+    return widget;
+  }
+}